This invention relates to a sun following-up device for use with a solar heat utilization apparatus which is adapted to focus the received sunlight and utilize the focused sunlight as heat energy for heating and cooling purposes.
In order to utilize the sunlight as heat energy for heating and cooling purposes, various researches have been made and being made. The applicant has developed a solar heat utilization apparatus which is adapted to condense the received sunlight and then convert the condensed sunlight into heat energy, which utilizes a light to energy conversion device having a small area and which can be produced at less expense. The solar heat utilization apparatus is disclosed in U.S. patent application Ser. No. 119,882, now U.S. Pat. No. 4,317,444 Australian Patent Application No. 55449/80 and European Patent Application No. 80100951.5 filed in the name of the same applicant.
The solar heat utilization apparatus referred to above is a so-called sunlight reflection apparatus of the two shaft sunlight following-up type and one of the most important requirements called for the apparatus is that the focused sunlight properly strikes on the heat collecting means which is provided at the focus of the parabolic trough of the sunlight reflector. For the purpose, the higher the condensing degree is and the greater the center angle connecting between the focus and the peripheral edge of the sunlight reflector is, the higher the preciseness required for the angular deviation between the sunlight axis and the optical axis of the parabolic trough reflector should be.
As one example, when the center angle of the sunlight reflector is 213.degree., the angular deviation is .+-.1.degree.5' for the sunlight condensing magnification of 27 times and .+-.33' for the sunlight condensing magnification of 54 times.
The angle of the vertical rotary shaft is especially required to be precise and as to the angle of the horizontal rotary shafts, even if the angle is not highly precise, a slight deviation of the angle of the horizontal rotary shafts will not present any serious problem if the length of the heat collecting means is extended by a small amount.
As the size of the sunlight reflector increases, it is required that the optical axis of the reflector is reorientated vertically so as to minimize the area of the reflector parabolic trough which faces the wind to avoid the influence of the wind force, the reflector is allowed to rotate freely under the force of the wind and the reflector is returned to the normal position when the wind velocity decreases. And it is also required that the reflector returns automatically to the normal position from the position which the reflector assumed at the time of interruption of electric current supply or at night.